I liked the actors; I liked the concept; but I only got around to watching this movie tonight. It's a pitch-perfect sendup of cult sci-fi fandom with, yes, heart.
An earnest alien race in need of protection mistakes a 70s-80s TV show for a factual account, assuming the show's cast (Tim Allen, Sigourney Weaver, Alan Rickman, Tony Shalhoub, Daryl Mitchell, Sam Rockwell) are actually the characters they play. I would've related to the movie when it premiered as a Star Trek fan. I relate even better now as a Firefly fan.